turbosanonymous

So after replacing , the solenoid, the starter, the battery, on my 1989 mustang i still cannot start the car. i have power to the key(lights,radio etc) but nothing when i turn the key. I use the screwdriver on the solenoid trick and it fires right up. Any idea what it could be now? Nuetral Safety, or ignition switch? And how do i test these?